General Jackson saw it at the same time.
"What is that ?" he exclaimed.
"It looks like a forest fire, general," replied Sherburne.
"You're right, captain, and it's growing." As they galloped forward they saw the red light expand rapidly and spread directly across their path.

The whole forest was on fire.

Great flames rose up the trunks of trees and leaped from bough to bough.
Sparks flew in millions and vast clouds of smoke, picked up by the wind, were whirled in their faces.
The troop of cavalry was compelled to pause and General Jackson, brushing the smoke from his eyes, said: "Clever! very clever! Milroy has put a fiery wall between us." The device was a complete success.

The pursuing men in gray could pass around the fire at points, and wait at other points for it to burn out, but they lost so much time that their cavalry were able only to skirmish with the Northern rear guard.

Then when night came on Milroy escaped under cover of the thick and smoky darkness.
Harry slept on the ground that night, but the precious cloak was around him.